top of the lawn

urban footpath | pavement | sidewalk astronomy from Central Park, New York City

Tuesday, October 31, 2006

Quiet Night

Session name: 20061030.0830Image of moon during this observation period. Photos are taken with Canon Digital Elph handheld to the Tak eyepiece.

Last night was a quiet night.

I arrived at TotL meeting Charlie who was already there. As I approached our turf I didn't see any of his gear. I shrugged and he picked up on this gesture where he held up his bins hanging round his neck. So you're going to be the tripod for Halloween

I brought the Tak bins and Harry. It was too breezy for Harry so I kept the Taks mounted most of the night. While I was fumbling trying to spot C/2006 M4 (SWAN) in the handheld Fujinon 7x50 bins, Charlie steered the Tak bins right on to it. Again the stars were washed out and I lost my bearings having to rely on Draco's Lozenge again and then navigate down to zeta Her up to epsilon Her. I never did see the comet in the handhelds. In the Taks it was obvious. No tail just a round condensation. The brightness was even and broad across then the illumination dimmed farther from the center.

It wasn't long before the comet set below the trees. From where we typically observe at the middle of the top of the lawn our northwestern horizon is obstructed by trees, one that rises to probably 30° or better. We could have moved east but hey! we saw the comet and got a quick sketch of it. Missed M13 behind the trees which serves as a convenient, comparative object for size, brightness, and character.

Instead we turned to the 8d 19h Moon. Once again it fascinated me and everyone else that took some looks. There were some new faces and dogs that stopped by. These bins can provide a nice view and pretty good with detail for the casual observer. The moon's phase also helped where Copernicus straddled the morning terminator. Under this illumination there is little hint that this crater splashes the landscape with ejecta. To the north Plato stood out well as an easy landmark to guide their observation about an outer ring one can trace with the Alps, Caucuses, Appenines, and the eastern edge of Carpathian mountain ranges. We could see the Alpine Valley interrupt this rough looking landscape/ the inner ring can be traced with the stuttered range of Mons Teneriffe and the lonesome peaks, Mons Pico and Mons Piton. Our focus leaped just south of the lunar equator using the crater trio: Ptolemaeus, Alphonsus, and Arzachel to find crater Thebit. Once there we could see Rupes Recta between Thebit and Birt. Later we'd look at this spot with the 6"reflector Harry using 74x magnification. Thebit's cascading craterlets on the successive northwest rims were apparent and Rupes Recta was just easier to observe.

Lastly, another popular crater was observed very close to the southern limb. Clavius had completed its emergence into daylight and carrying the craterlets arcing across its floor. Rutherford appears as the largest of these on the southern rim while crater Porter is counterpoised on the northern side.

The sky was pretty much clouded except for a general area around the moon. I did hop to Uranus coming up from Fomalhaut but it was not easy because of the clouds hiding the stars I needed. Since Harry was grounded and the cloud cover was over most of the sky, I decided to pack up early.

Usually I feel a lull from those dark sky trips but a brief interlude at the bright statued location on 6th & 59th helped to ease my return to TotL.

Monday, October 30, 2006

The Comet, The Moon, and Mrs. Sherman

As we sat in our living room having a Sunday picnic, we could see out the window to the south a low hanging first quarter Moon. It looked like the terminator was drawn right down the exact middle. I looked to the wife, gave her the look, and then packed the grab-n-go bag.

In a short time, I arrived at the statues at the mouth of Central Park, 59th & 6th and setup the tripod and Tak bins. While there I decided to look for Comet 2006 M4 (SWAN). From this location, it is awfully bright from the street lamps and passing cars. Initially, I had to hop into Hercules by starting at Vega out to gamma- & Beta Draco, the two brightest stars of the head (Lozenge). Back down to zeta- & pi Hercules. As I sighted down the Tak tube to align the bins with zeta, I landed on Comet 2006 M4 (SWAN). It was obvious as a moderately bright condensation. Form my location in all the lights, I compared its brightness with M13 and say that it was slightly brighter M13 judged by the ease of detecting it. Its difficult to say if one was larger than the other as I made no notes of this.

I moved the tripod more west into the middle of the feeder street. From where I stood, I could look straight down 6th Ave., also called the Avenue of the Americas. It's an uptown avenue meaning that traffic flows uptown. From behind the police barricades, I set up the tripod in the middle of the park entrance street with headlights coming straight at me. At an azimuth of around 213°, I can see First Quarter Moon down the Avenue of the Americas. I stood and sketched Moon while it crossed the street occasionally catching some glances but no one stopped.

Until a woman passed by with what looked to me like the skeleton of a two story Lazy Susan, who I'll call Mrs. Sherman. With a chrome stem and base plate, Mrs. Sherman, thinks possibly otherwise. Her husband is an artist and she thinks that between the two of them they'll come up with an idea for it. Otherwise, back into the bins. As Mrs. Sherman was passing with Lazy Susan in hand, we made some eye contact and lonely as the sidewalk astronomer, I invited her for a look at Luna. She came over and took some peeks through the bins. I described some of what we saw and referred to the sketch once in a while to get our bearings. It turns out we spoke for a good period of time and looked at the sky naked eye with limited success.

We walked a short distance from our things to get a better view of Perseus who was obstructed by the trees. We spoke briefly of mythology that exists in that part of the sky. Mean while, the Lazy Susan stood at the foot of the tripod-mounted binoculars. While talking with one another we took turns looking at our stuff, making sure that no one would walk off with any of it.

Moon was spectacular as she usually is. Archimedes served as a landmark for the terminator in Mare Imbrium. The mountain ranges, Appenines, Caucasus, and Alps rose majestically, easily rivaling the Rocky Mountains in emotion. There shadows black to the west help in creating more depth of field. A lone mountain peak sitting on the floor of Mare Imbrium, Mt. Piton, casts its black, pointed shadow to the west. It reinforces that it's morning here on the Moon and the Sun is rising. Over the next couple of nights, we will see this and the other shadows east diminish in size. The southern hemisphere is bombarded with craters, too many for me to sketch convincingly or with any realistic likeness. I stick with just getting the proportions of mare, their relative shades, and positions.

In the end, Mrs. Sherman and I exchanged our names and wished each other well. It was the end of the day and a good one at that. I was happy to have gotten my first sight of the comet with little effort, kick around on Moon, and pass some the time with Mrs. Sherman. There are only so many first quarter moons, or equivalently trips around the Sun, so the more people I meet and the more joy that people can gain from intersecting with an amateur astronomer, it makes those small arcs of the orbit that much more worthwhile.

Among some giants

I went to Adorama on Sunday (29 Oct. 2006) to replace two eyepieces lost last year. I've bought most of my astronomy gear from them as they have earned my trust and favor over the years. When I went inside, there was Josef, the usual counter person sitting at a renovated counter. Where there had been astronomy stuff, like an eyepieces, binoculars, spotting scopes, tripods, etc had now been cleared. I asked, "What's up?"

Josef said that the Astronomy Dept. was now on the fifth floor and that Tele Vue was up there. "Okay, are there discounts today?", I asked with a smile. Maybe, check it out, they're all up there on five he told me again. I asked if Peter was there, and he said yes along with a bunch of other names I didn't quite catch.

Back in the early winter of 2003, when I first adopted astronomy as a hobby, I took an astrophotography class at The American Museum of Natural History/Hayden Planetarium which was taught by Peter Lipschutz. With the same technique and equipment I use today, I attended the class and got to show off my lunar photographs taken with a Digital Elph, Tele Vue Ranger, TV Plossl 20mm & 32mm, and rubber bands. Peter works at Adorama and I'm am glad that he was there as he was the only person I knew.

Al Nagler was there demonstrating his eyepieces in a few of his scopes to someone and I wanted to introduce myself. 95% of my eyepieces are Televue and with the exception of a Plossl 20mm and 32mm, the rest are Naglers. I also have a TV Ranger, no longer produced, that use occasionally for my grab-n-go pack. Also I'll use it for imaging or what has been recently termed, digiscoping. While waiting for a break to engage Al, I chatted with Peter and turned out to be for a good period.

I was floored by his photographic work. There were 3d glasses and lunar landscape pictures all about with that familiar red and blue offset color. Donning the glasses, I was immersed in these photos. They ranged from macroscopic work to urban landscapes to still lifes of acorns and dried leaves to lunar landscapes to a large wall sized mural of the interior of a Martian crater. in another corner of the room below one of the floor model telescopes there was one where you stand on the lip of the crater which had a crater in its wall. Equipped with the 3d glasses, I could reach down and insert my hand in the craters. "Insane!" In my moments of awe this is my utternace.

Peter wrote an article about the technique. If you're in NYC, make an effort to drop in at Adorama on the fifth floor to see this work. After looking pictures this way it makes one wonder why all photographs couldn't be produced and "consumed" like this.

Another gentleman who worked there, MikePeoples, shared his work as well. He described how he and a number of other amateurs are discovering supernovae in other galaxies. He's got quite a few under his belt in addition to a cataclysmic variable he discovered. Wow! I'm not entirely certain but he seems to make his livelihood from amateur astronomy - and, maybe a little help from retail. I was totally impressed by his stories, his astrophotography, and his charitable involvement with the art & science of amateur astronomy.

Later I spoke with Al Nagler of Tele Vue fame. Absolutely a celebrity in my eyes and having the privilege to meet him was more of more treats. I can't imagine this man is not loved around the world. I was struck by the attention he gave to each of us that spoke with him. He gave sme tips on selecting eyepieces and showed off a few of the TV APO refractors. I told him how I lost my eyepieces last year, most were Naglers, and he shared his story of loss in Australia. Sort of took the edge off my grief. Thanks, Al.

At the end of it all, it wasn't the baseball cap they gave me or the door prize of a gorgeous 24" x 24" print of M42 & M43 or the new eyepieces I got that made this a special day, but the charity and encouragement these men shared and allowing my three years to participate with decades that these men have. Collectively, I would say there was a century and half plus three years of astronomical experience to contribute to the betterment of humankind.

Sunday, October 29, 2006

M45 & visual acuity

Speaking of M45, of late I have been able to resolve 8 stars pretty easily and sometimes as many 11. I don't know if it is the skies have becoming increasingly dark and more cleaner, I doubt it, or that my visual acuity is improving.

The integrated brightness of Asterope typically appears soft and easier to detect than Celaeno,which sits almost central and slightly to the west of Taygeta & Electra. It takes a clear steady night to see Pleione just north of Atlas. When I get it, I get it but sometimes it is not as clear and distinct as Asterope or Celaeno. Occasionally, I get other stars that are nearby, especially one that makes a right triangle with Atlas & Alcyone, maybe a degree to the south. Another to the northwest of Asterope can blink or be seen.

Not bad for the city, but as for a transparency indicator it really only makes sense for me.

Using M43 for calibration

Browsing through the blogs I regularly visit, I came across his sketch which stirred memories of a recent outing in dark sky. At one point in the evening, we were observing M45, particularly looking for Merope Nebula. Instead I saw, or claim to see, nebulae around at least three of the Pleiades. Others said it wasn't, passing it of as flare/glare in the eyepiece, eyepiece defects, bright star irradiation, etc. Each nebulous patch did not surround the stars equally. To me, it was unmistakable as a grayish white nebulosity that was very pronounced in a southerly direction.

Which brings me back to M42 & M43. Actually, it is M43 that is of interest. I use M43 as a benchmark to set my expectations when looking for other faint, low surface brightness nebula, for example like M78. (I can also use the far reaches of M42 to the west/southwest to calibrate my expectations.)

In Jeremy's sketch one can see M43 around the star northeast of M42, to the upper left and similarly with the photo on SEDS. My experience has been that this nebula is difficult and not as large. And oftentimes, M43 doesn't have enough punch to show in our urban skies or requires averted vision. When I detect it, M43 typically hugs the star and sometimes pulls away in the opposite direction of M42, shaped like a "comma".

So after the others said they did not see nebulosity around M45 the 18" scope was swung to Orion's Nebula. What good fortune because I was able to see the M43 and the far reaches of M42. And by the looks of M43, which was visible but not spectacularly brilliant, it affirmed my confidence of seeing the nebulosity. In fact when M42 came up no one mentioned M43. I asked one other if he saw M43 but he said he was uncertain. My notes don't indicate a comparative brightness between M43 & M45, which I could do next time.

With that said, I was led to believe that none of the observing party had seen M45 nebulosity before because no one stated it or remarked to the contrary that they had seen it. Hopefully a time will come when I get to see it and then have an experience to rely upon.

Wednesday, October 25, 2006

it's a whole different ball game

being an avid new york city observer I look forward to our infrequent trips to the darker sites, as we did recently. having too much of a good thing I experience something like a hangover from dso's and lots and lots and lots and lots of stars.

This morning Charlie and I met at CSP primarily to catch the last crescent Moon. Arriving at the park early enough I concentrated on some deep sky hopping while Charlie did some meteor counts to determine the zenithal hourly rate (ZHR).

I had the Taks set up to calibrate landmarks on the horizon with azimuthal measurements. At.6% lunar illumination this was going to be tough and knowing where to look is key. If the field of view is setup properly one can concentrate on working with your eyes and focusing to detect the low contrast crescent Moon rather than trying to find it with sweeps or scans of field. Like most things one has to know where and what you are looking for.

It turns out that this crescent was undetected. I may have been looking slightly too far north at the time, like half to three-quarters of a degree. The sky brightened considerably but I believe this was doable. Next time... ;^ D

After getting my bearings on the horizon and waiting for moonrise, I did some starhopping with the Taks in Canis Majoris, Puppis, and Monoceros. I looked at mostly the bright Messier open clusters and the tiny cluster that hugs tau Canis Majoris. Afterward I laid back on a park bench, threw up a towel along the backrest to shield the light from my eyes and scanned the sky with 7x50 bins. Wow! really beautiful sky even if it is a bright city sky. Wonder churns in my head as I look to star-studded sky around Orion's Belt and the stellar nursery in the Sword. There are other people out there. That blister on the giant molecular cloud is there grab our attention.

The photo above created by Cartes du Ciel and RealSky Survey shows a field of view that includes 3 clusters. The two larger, brighter ones at the bottom are M46 and M47. NGC2423 is the knot of stars above M47 which is to the right. M46 is a low surface brightness object and not easy to see in the city without a lot of glass. In the 4" Takahashi refractor this open cluster would not disclose itself until I got the 10" on it. I haven't tried the 6" reflector but suspect that it may do the job.

As for the meteors, I wasn't that interested and saw at least a dozen and probably more without any effort. I would look up a zing! across the sky they flew. It would be the later this day when we went to dark sky that a phenomenal meteor show was put on.

Weekend sunrises

Saturday morning, 20061021.0725. Sunrise at Carl Schurz Park. Chased the last crescent moon but unsuccessful. Beautiful sunrise while the promenade offers a sample of the growing energy for a day in the city.

Sunday morning, 20061022.0725. Fabulous sunrise where we saw "Omega" form hoping to see a green flash. We missed that, too, but we did see a phenomenal sunrise that exhibited a lot of character from a tube-shaped Sun to Omega when it detached from a second inverted Sun. All this on the horizon looking out from Orient Point, Long Island, New York after an all-nighter at Custer Institute. (Maps: google || Live Local)

One of a series of photos showing Sun. (Not much happening in terms of sunspot activity, just a few in the northeastern quadrant.)

Sunday, October 15, 2006

Urban Starfest

Session name: 20061014.2000Location: Sheep'sMeadow, Central Park, NYCMoon Age/Illumination: 22.5 days/40.0%Conditions: Very clear, transparent skies. Windy at times and chilly, dipping into the 40s. New York Gegenschein from CitiCorp & Times Square appeared more pronounced and reached higher up to 70° ~ 80°.NELM 5.0++Companions: Kin and Tom C.

Equipment: Harry, 6" F/6 reflector mounted on a Bogen 410 head on a Bogen 3221WN tripod. Shaky mount and the light optical tubing made of foam core catches the wind easily, earning the nickname, "Kite". The wind died down and the scope steadied providing great views of the open clusters.

--- * ---

Tonight the Amateur Astronomer's Association (AAA) membership held its annual public outreach event, Urban Starfest. It's a 16 year old event where the Urban Park Rangers partner with the AAA to introduce, raise awareness, and celebrate astronomy under New York City skies. My guess was that there were nearly a dozen scopes, give or take a few more, ranging from tripod-mounted bins to small scopes like a Questar and an Astroscan to larger 8" Schmidt-Cassegrain to the largest scope, a truss tube 12.5" reflector on a Dobsonian mount. There appeared to be a number of 60mm ~ 80mm refractors.

When New Yorkers come together for a common good, like anywhere else, the feeling and inspiration is moving. This session shared that quality. I met up and chatted with a number of the membership including Rich Rosenberg, current President of the AAA and Mike O'Gara, past president of the AAA. And like past years, I got the chance to say hello, chat, and observe with Lynn Darsch. Dan Harrison made some rounds and we spoke of Canadian Rockies and a few of the activities that AAA offers to members and the public. Rik Davis was there whom I see more frequently than others. He is the chair for the Observer's Group meeting and conducts the monthly public observing events and in the park. I missed to see Bruce Kamiat and Alice Barner. These two persons are instrumental in enabling others to pursue an interest in astronomy. I think they attended another AAA event elsewhere in the city.

I also got to meet a number of other people both in and out of the club. In the dark I have a hard time with faces and names needing reinforcement from repeated contact. But one new face, George, will be easy to remember since he is a fellow Teleport telescope owner, #TP10-027. This makes us cousins by way of Tom Noe.

--- * ---

When I arrived it was breezy so I left Harry strapped to the tripod. Seeing that Mike had setup 12.5" reflector, I wanted to see if it was enough to bag M110. This galaxy has escaped detection in NYC skies with repeated tries using the 10" Teleport and once with a Meade 12" reflector. So I *ran* up the 12.5" where Mike invited peeks of M13, the best I've seen in NYC. I asked if he could try for M110. He kindly swung the scope around the sky and offered the view. This galaxy's surface brightness is apparently too low to yield a great enough contrast to see it. By my calcualtions this thing should be do-able. Unfortunately, it seems like more glass is needed. But how much!?

There was a little chatter that the public may not have been informed of the event. I thought it was a great success with the turnout of scopes and people. I suppose there were more members than general public but I thought it was pretty busy around Harry. But that was exactly what I admired most, seeing the club congregate and celebrate together. I would have liked to look through others' scopes but I got caught up in pushing the scope around and chatting with people that I didn't have much an opportunity.

And with urban astronomy outreach, I think the talk is as important as showing the object. Since the objects lack that spectacularity that is experienced in dark sky views, the description and story are to fill in for any lack of visual fascination. If I taped myself I probably sound like a broken record ~% D Some of these folks have their talk down well, something I could work on.

What follows is a list of objects observed with Harry. With the exception of the Double Double and Uranus, all the objects were observed with low power at 30x in a Tele Vue Plossl 32mm eyepiece. The other two occasions A Tele Vue Nagler 7mm T6 provided a 135x power. Over the course of the session there was a sample from each class of deep sky object - double star, bright nebula, open cluster, globular cluster, galaxy - though open clusters were greatest in quantity. The one object variable star I missed to point out, especially with Algol rising. I'm certain someone else pointed this out.

- Solar System -

Uranus. Under high power we saw the small, bluish disk. Even at low power the planet is a steady solid disk of light contrasted with nearby lambda Aqr.

epsilon^1 & epsilon^2 Lyr. The famous "Double-Double". This was by request from the first person who came by the scope. At 30x both epsilon^1 & epsilon^2 Lyr appear as a wide double, 208" separation. At 135x, both stars resolve as close doubles where there position angles of the pairs are almost perpendicular. epsilon^1 mag 5.4/6.5 sep 2.6", epsilon^2 mag 5.1/5.3 sep 2.3".

NGC 869/884. Double Cluster. In terms of showing the objects to the public, the Double Cluster has to be the highest on the list for ease of observing and generating a response from non-observers. In contrast to a bleak steel gray sky naked eye, this field is rich! Rich with knots of stars and concentrations of stellar dust. The background sky is mottled from the unresolved starts of the Milky Way. Some find it fascinating when hearing the description of our galaxy and that they are looking into the Outer Arm, a.k.a. the Perseus Arm further out into space.

Stock 2The Muscleman Cluster is nearby and was placed in the eyepiece for inspection to offer a greater variety of open cluster character and quality. In the 2° field of view this large, loose open cluster rich in stars with a narrow range of magnitude almost fills the entire field. This object also provides an opportunity to describe the different persons involved with cataloging objects in addition to Messier, Herschel & Dryer, and open clusters in particular like Trumpler, King, and Collinder to name a few.

NGC 457, Owl Cluster/ET Cluster. Second only to the Double Cluster, most persons were impressed by the Owl Cluster. It's fun thinking of a familiar object and decoding this form from the stellar arrangement. First, phi Cas and its secondary are bright enough to draw the eye in and then the fainter stars fall away forming the sine and legs with outstretched arms. It doesn't take much from the imagination to connect the dots to see this shape.

NGC225, NGC581 (M103), NGC663. I showed to some that passed by these open clusters in Cassiopeia. The intent was to show the variety of character these celestial objects can exhibit. Also, each of these objects is a very easy starhop from nearby naked eye stars. NGC225 is just north of gamma Cas while M103 & NGC663 are east, northeast of delta Cas, Ruchbah. NGC225 stood out as a moderately bright, irregular cluster, I would describe as a backward "C", which is bottom-heavy with a concentration of stars. In comparison with NGC225's size, about 15 arc minutes, NGC663 appears equally as large but with a more bright, hazy patches to each side of the central bright stars. In the hazy patches, stars twinkle into resolution and are lost again into the haze. A pretty sight that mimics the behavior of "virtual particles". M103 is nearby and actually first seen when hopping from Ruchbah. I find it as an unimpressive cluster and is not easy to describe to the public. In fact a tiny knot of three stars appears further east that some are confused by. Similarly, Trumpler1 is in this area nearby but would be difficult to point out and lacks that "spectacularity" that other objects can emote from the observer.

M34. Another easy, bright open cluster in Perseus but on the other side of Mirfak. M34 is easy to find since it is large and bright. I usually hop off of kappa Per and move ~5 west or one can look at a spot halfway between Algol and Almach (gamma And). On first glance I am struck with the impression of two concentric rings of brighter stars and the middle contains a loose concentration fainter stars.

- Bright Nebula -

M57The Ring Nebula. The only bright nebula observed. Since I was nearby with the Double Double I swung the scope on this nebula, later by request I picked this object again. At 30x, this object was very faint against the background sky, obvious to a trained observer but not the best object for the public since it is hard to pick up and some may need to use averted vision without experience. Sheliak, beta Lyr, is a bright double star with a fainter secondary that I typically hop of from on my way to M57.

- Globular Cluster -

M13. This was the first object I observed and fine tuned the alignment of the paper towel tube that serves as the finder. The woman who asked to see the Double Double was the only who observed this globular in this scope. In contrast to the view in the larger scope, this view exhibited an even, pale glow across the entire object.

- Galaxies -

M31 & M32. Andromeda Galaxy was another popular object, probably the most requested. Andromeda Galaxy is bright enough to be seen in any size instrument. It takes a larger instrument and steady view to pullout M32. In the 6", it was fairly easy to see the small right triangle to the south of the M31 where the farthest star is blurred and doesn't resolve. Much can be told to the public about Andromeda, especially as a specimen which to describe the likenesses it exhibits.

One can describe the evolution of man's understanding of our galaxy referencing men like Kapetyn, Shapley, and Hubble. It wasn't until the 1920's that Shapley began to describe our galaxy in its truer size and our location within it.

Andromeda Galaxy is a classical spiral galaxy to fascinate new observers and the public. We can see the bright nucleus and core as a fuzzy "cotton ball" in the eyepiece. We register this light that left the swarming cluster of Population II stars in that galaxy 2.2 million years ago With a diamter of about 150,000 light years, Andromeda Galaxy is larger than the Milky Way, and the largest galaxy of our local group. In 3 billion years or so, Andromeda and Milky Way will collide and most likely combine. Both galaxies have already acquired smaller ones.

Even though this was an occultation event, I could not help but admire Moon in the clear, crisp Fall night. Mare Crisium almost engulfed by sunset projected itself with the broken western wall casting shards of light on to the mare floor. Normally described as smooth, this scene revealed a molested ground with ribbing, craters and detached hills. Light and shadow intersected. Collided violently.

And if I looked to the background stars I could see that Moon covers some ground - reasserting Galileo's whisper in another context- "Eppur si muove". Yet caught in each moment the Moon is delicate as teardrop suspended in the space with in my eyepiece. I sort of get the same feeling naked eye, but not quite. The magic happens in the eyepiece.Prior to the event I copied John Pazmino's timeline for the event and planned around that. His information appears as follows, copied from PazMiniBits, Oct 2006 obtained from the NYSkies Yahoo group.

Times by my wristwatch. Actual timestamp may not be accurate, but the intervals between events should be close. When an event is indicated that I saw it, a margin of error from 1~2 seconds may exist from spotting the event and then looking to the wrist for time.

Takahashi 22x60 bins, tripod-mounted00:01:29 - Electra disappears, up to pimpling on limb, time stamp to when I thought "D"00:10:18 - Celaeno disappears, difficult, lost in the glare as it approached limb

Asterisks indicate a degree of uncertainty or a greater degree of error. All the reaapearences were "snap on", except Celaeno.

I observed the last two reappearances at 135x & 34' field of view using a TV Nagler 7mm T6. Sterope II sort of felt drawn on - it still blinked but I had a sensation that it had gradual brightening versus the others that I had seen.

After the event was over, I spent some time walking along the crater rims of Atlas and Hercules. I descended into the crater inside of Hercules, trying to avoid the blackness but no use. Eventually I arrived at the southwestern wall climbing back into the light. There was another craterlet sitting atop of the rim. Imagine perched on top looking to the northeast and the horizon falls away hiding Atlas from my view.

As I mentioned earlier Mare Crisium was fabulous. M. Crisium also has craterlets along the top of its rim. I counted three. Is there anything more striking than Mare Crisium in sunset?

Sunday, October 08, 2006

20061007 - Moon persists in spite of clouds

Session name: 20061007.2155Location: Top of the Lawn, Central Park, NYCMoon Age/Illumination: 15.6 days/98.6%Conditions: Clouds came and went all night long from overcast to mostly clear. Some boiling on lunar limb. When clouds cleared transparency was very good. All 7 Little Dipper stars & the usual suspects in Cassiopeia, Perseus, Hyades, and Pleiades.NELM: 5.2Copanions: Charlie, Kin, Hawaian GeorgeDog walkers: Carole, Andy, Diderot

This session we concentrated on Moon. Even though the clouds were a distraction all night we were able to get in some of the brighter deep sky objects and mostly Moon. The clouds did not hide the lunar disk rather attenuated the glare to make for some nice naked eye observations and also for some delightful study in the scope.

Naked eye we could see Mare Crisium detached from the three prominent maria on the lunar eastern hemisphere and a large white bright patch where Tycho sits prominently the southern hemisphere. Personally I couldn’t resolve Tycho to a precise spot because there was a lack of contrast to distinguish the crater from surrounding ground. However, on the western hemisphere Copernicus, Kepler, and Aristarchus were clearly seen. Charlie was able to resolve Grimaldi but I couldn’t see it. Below Oceanum Procellarum Maria Nubia and Humorum were visible but not like a detached feature as displayed by Mare Crisium.

For the first part of the observing session the Tak 22x60 binoculars were on the tripod to observe brighter DSOs descending in the west. When clouds moved in Moon was the obvious object to check out.

Spectacular! Moon looked spectacular framed in that 2.1° field of view. The disk was full bright but no glaring because of the clouds and the terminator offered beautiful relief of cratering just inside the eastern limb. I didn’t scrutinize any specific area or feature as I did with naked eye or the scope. I just sipped on the view as if my eyes were savoring a lunar bouquet. When Hawaiian George stepped up to the eyepieces, I heard him exhale and utter sounds of wonder.

With Harry 6, the reflector, two eye piece combinations were used: A 2x barlowed TV Plossl 32mm & a Nagler 7mm T6. A huge step between the two but provided two distinct views. In the north Endymion serves as a landmark that I check for libration and as home base for a meandering hike towards Mare Crisium. Craters Hahn (with a central peak) & Berossus were the first to catch my attention. Already lost in the evening terminator, crater Gauss resisted with part of its feature rising above the effects of curvature still shining in the sunlight.

Imagine. Descend the face of this feature and reach a point where it’s lights out! Without an atmosphere there is no twilight, either there’s light and warmth average (224°F/107°C) or the other extreme nighttime and coldness (-243°F/-153C°). Without going into much detail, as those places on Moon enter nighttime, they see a crescent Earth wax to Full Earth over the next 13 ~ 14 days.

While up in the north, we hiked through the dried river bed of Mare Anguis. This irregular shaped mare just north-northeast of M. Crisium looks best as nighttime unrolls on this region. On the rare occasions that I observe his feature under this kind of light, I am struck with the impression of large river bed that winds it way into a wall of darkness.

I still can’t identify a feature that Charlie, Kin and I observed in the south-southeast limb just on the horn of the terminator. I was uncertain if it was part of Mare Australe going into the terminator or if it was a feature more in the southerly direction along the limb. I searched for Clavuis to get my bearings but had a difficult time to locate it as it apparently washe out under the sunlight.

Charlie dubbed one feature, “Palisade”, after the cliffs that New Yorkers can clearly see across the Hudson River. It appeared to be the face of a high crater rim where the top was still painted in light but the face was pitch black. Strangely there were two spots on the face of this cliff that were bright. It didn’t make sense how they could catch light but Moon is a sphere and not a plane.

The southern hemisphere is riddled with craters. I like how the effect of foreshortening increases for craters near the limb. Brightr crater rims interwove with black lined crater floors as if we were getting a peek right over the wall. This really enhances the feeling that we are looking at a 3 dimensional orb in the sky.

With clear skies forecasted tonight, I’m sure that Moon will be on the top of the observing list.

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Interested in the Moon for your desktop. This image form Vern's web site has been my laptop's desktop from the day I saw it. From time to time I go back to his lunar archive to peruse the images he shares with us.

If I had to recommend one lunar atlas for the beginner, without hesitation, Photographic Atlas of the Moon, Cambridge University Press, 2002. I am not fluent with Moon and often refer to this after binocular and scope observations. I admit that I complement this with other resources like the Internet or otherbooks but it is usually the first thing I grab for to identify a feature I'm not sure about.

This atlas is great for anyone learning and exploring Moon day by day. Typically four pages provided for each day:- First verso has a description of a terminator tour, not overwhelming in detail which I like. It makes for the reading light and one can refer to another book book for a denser treatment.- First recto is a 3/4 page photograph with markup notating the features described. The lower quarter page lists all the features notated in the photograph.- Second verso has a collection of close-ups and photograph specifics of the features.- Second recto has the same image as the First recto without any marks.

What I like most is the light writing and clear descriptions of the features that authors S.M. Chong, A. Lim, and P.S. Ang provide in concert with the bright and readable marked up photograph; nothing like that seen in Cherrington's Atlas. The book is appendixed with organized lists for further reading, lunar features, description of the lunar phases, and a chronology of mapping Moon.

Sunday, October 01, 2006

Ancient Egypt

Of all the civilizations of antiquity, the Egyptian seems to me to have been the most pleasant.

- Otto Neugebauer

When I think of ancient civilizations and astronomy, Babylonians, Greeks, and Arabs immediately come to mind. Almost instinctively I want to group the Egyptians since they too represent a prominent civilization of antiquity. However, Egyptians don't figure much in the history of astronomy, yet they figure a lot in our exit from the Top of the Lawn.At the completion of most observing sessions at TotL, we exit the park to the east, passing The Metropolitan Museum of Art (The Met). A glass wall spans nearly the enitre depth of the building and rises more than 60 feet to display the Met's Egyptian collection. I don't give it much notice other than silent acknowledgement that it is big and impressive. The lawn between the sidewalk and glass wall has always been a disciplinary boundary which kept me back.

A recent evening when we left, a couple of clusters of kids were seen sitting on the lawn beside the museum. I was surprised because I didn't think anyone was allowed there, especially so close to the museum. One group of three had lit a candle and they were singing as one of them strummed a guitar. Nearby another couple sat and chat while over their heads I could see through the window a museum guard sitting in a chair. Another group of kids ran right up to the window and walked the building's length in toward the park. Charlie gestured with arm, "Come on." And off we went up to look at the treasures.

Looking through the window the Temple of Dendur anchors the west part of this huge room. In the foreeground just in the other side of the pane of glass is a sarcophagus. Further down the room to the east statues stand against the wall. Pretty impressive that these structures and works of art are the handicraft of men 2000 years ago!

This is a picture of the gate of the Temple of Dendur. Made of sandstone, it comes from ancient Nubia some time around 15 B.C. Its total length from gate to rear of temple is 82 ft. The temple, with its gate facing the Nile, was built into a hillside in Upper Nubia where the river valley is very narrow. Originally the gate was set in a high wall of mud bricks that surrounded the temple, but gradually recurrent high water destroyed the wall.The gate figures prominently here with the temple in the background at the lower right of the photograph. Atop of the gate the lintel is reconstructed with another material to depict its original structure.(A map of ancient Nubia? or Nubia at Wikipedia)

maintenance : backup

First time I performed a backup of this blog. Using these instructionsI tested the steps on another blog and then on this one. Pretty straight forward and the whole process, backup & restore, only takes a couple of minutes.

Ideally, step #3 where one changes the Blogger template could state explicitly that one clicks the button:[Save Template Changes]before moving on to the Settings section to make the Formatting and Archiving changes outlined in Steps 5, 6, 7, 8. The same holds true for each of these steps where one saves changes before moving from one tab to another, i.e. Settings | Formatting to Settings | Archiving tabs.

For a first timer, there's a little anxiety that things can get lost or unrecoverable. But the instructions are well written and work like a charm.